The Community Child Health Network (CCHN) Phase II research proposes to: (1) advance understanding of the combined biomedical, social, behavioral, and environmental influences on the course of prenatal development, pregnancy outcome, and early child development, particularly in physical growth, respiratory function, and language development. CCHN proposes a 5-site, longitudinal study of 2 integrated cohorts: a Birth Cohort Study of 5250 families (1050 per site)) followed by a Subsequent Birth Study (38 percent of mothers expected to have a subsequent livebirth). These studies focus on the role of stress and allostatic load, as moderated by resilience and supports, on pregnancy outcome, fetal programming, and child development outcomes of prematurity/intrauterine growth restriction, overweight, asthma, and language and cognitive development;and (2) to develop and document active community participation in all phases of the study through the community based participatory research (CBPR) in the community-academic partnerships (CAPs). The findings are intended to advance theory about the etiology and impact of health disparities related to pregnancy and early childhood outcomes, as well as inform the design of future preventive interventions. Innovative features include: 1) focus on the inter- and pre-conception period;2) combining biomedical and psychosocial indicators and outcomes within an integrated conceptual framework;3) multidisciplinary measures of resilience and supports as well as risks;4) including fathers as integral to both pregnancy and child health outcomes;and 5) a participatory research partnership of the community and university at local sites and the national network. CCHN-LA is comprised of academic partners from UCLA and its affiliates (Cedars-Sinai, Good Samaritan, Harbor-UCLA, &King-Drew Medical Centers) and community partners in South and Central Los Angeles organized by Healthy African American Families (HAAF). The strengths of CCHN-LA include expertise and extensive experience in CBPR, stress and allostatic load, resilience and support, preterm birth, racial-ethnic disparities in perinatal outcomes, and research methodologies including study design, measurements and data analyses. CCHN-LA will enroll and follow 1050 families (15 percent African American, 65 percent Latino, 20 percent non-Hispanic White;also 80 percent poor and near- poor) residing in the Harbor Freeway Corridor and adjacent areas of Los Angeles County.